Automatic air-brake



(No Model.)

R. M. MCKINNEY.

AUTOMATIC AIR BRAKE.

110.311.1916. Patented Jan. 27, 1885.

Mill LE 5 5 E 5 N. PUERSV Phomiilhcgrapher. wflsmngmn, no.

UNITED STATES ATENT ROBERT M. MCKINNEY, OF ELIZABETH, PENNSYLVANIA.

AUTOMATIC AIR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 311,196, dated January2'7, 1885.

Application filed May 19, 1884. (No model.)

T 0 aZZ whom, it may concern.-

Be it known that I, ROBERT M. MCKINNEY, a citizen of the United States,residing at Elizabeth, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inAutomatic Air-Brakes; and I hereby declare the following to be a full,clear, and exact description of the same, reference being had to theaccompanying drawings, in which V Figure 1 is a perspective view of myapparatus as applied to a car. Fig. 2 is an end View, partly in section.Fig. 3 is an enlarged sectional View of the valve-chamber and anelevation of the mechanism for controlling the brake or brakes which areto be applied.

Like letters refer to like parts wherever they occur.

The object of the present invention is to so utilize air-pressure inapplying and releasing brakes as to place the brakes perfectly withinthe control of the engineer, so that he may apply the brakes alike toall the cars in the train or to the cars singly or in groups at any partor parts of the train which may be previously determined upon by theofficers; to provide means whereby the brakes will be automaticallyapplied to both sections of the train in case it should part; and alsoto provide means whereby the conductor may apply the brakes to theseveral cars of the train, having the same control thereof for suchpurposes as the engineer. The brakes are both applied and released bythe power of compressed air, and the method adopted is to alternatelyreverse the pressure on a piston or like device which controls thevalves of the brake-cylinder.

The main feature of the apparatus there fore consists in the combinationof a brakecylinder, a reservoir, a main supply-pipe, a valve-chamberwhich communicates with both the reservoir and brake-cylinder, and avalve so arranged within the valve-chamber as to be moved by either thecompressed air in the main supply'pipe or the compressed airin thereservoir, accordingly as the pressure is great er in the one or theother. A second feature, especially valuable in this connection, is thec0mbination,with the valve which controls the passage between thereservoir and brake-cylinder, of means for balancing the valve againstthe pressure in the reservoir, so that a greater or less reduction ofpressure will be required in the main supply-pipe to operate the valve,and of means for relieving the valve of the added power when firstmoved, so that the decrease of pressure in the reservoir shall notpermit the closing of the valve between the reservoir and brakecylinder.

I will now proceed to describe my invention more'specifically, so thatothers skilledin the In the drawings, A indicates a brake-cylinderroneof which is placed on each car, and has its piston-rod 6 connected withthe brakes, so as to operate the same. B indicates asuitable reservoir,likewise located on the car, and C an interposed valve'chamber.

Extending along the train from a suitable pump on the engine is aconducting-pipe, a, which is connected with the cylinder A and reservoirB of each car by a branch pipe, I), provided with a valve, 2', by whichit can be closed when any car is to be out out of the train. This branchpipe b delivers into one end of avalve-chamber, G. The valve-chamher 0(see Figs. 2 and 3) is preferably of-cyart to which it appertains mayapply the same.

lindrical shape, though any other form desired may be employed, and isconnected with the reservoir B by a pipe, 0, having a check valve, r,which prevents the return of the air when the pressure is lowered inconductingpipe a. Itis also connected with one end of the brake-cylinderA by a pipe, j, having a reducingvalve, K, which will be hereinaftermore fully described. The rcservoirB is connected with the upper part ofvalve-chamber O bya pipe, f, and the upper part of the valve chamber isconnected with the opposite end of the brake-cylinder A by a pipe, h,which may also be provided with a reducingvalve, K, if desired.

WVithin the valve-chamber O is a piston, Z, or disk,arranged so that itsopposite faces are acted on by the pressure of the air in theconducting-pipe a and in the reservoir B. The rods of piston I carrythree valves, one of which, n, is adjusted so as to control the portt',leading to one end of the brake-cylinder and its exhaust-port p,another, a, to control the port 9, leading to the other end of thebrake-cylinder and its exhaust-port q, while the third valve, 0,controls the port (I, which leads from the valve to the reservoir B. Theport (or pipef) leading from the reservoir to the valvechamber 0 isalways open, so that the press ure in the reservoir is constantlymaintained on the upper face of piston Z.

The devices thus far described embody the first point of theinvention,and operate as follows: Air under the desired pressure passesfrom main or conducting pipe at through pipe I), (and finding the valvesof G in the position shown in Figs. 2 and 3,) enters pipe j, passesthence into brake-cylinder A, and,forcing the piston thereof to theopposite end of the cyl inder, (if it is not already in that position,)takes off the brakes. The air also passes by pipe 6 to the reservoir B,and thence by pipe fto the valve-chamber O on the opposite side ofpiston Z, from which it originally entered valve-chamber C. As thepressure is now equal on both sides of the piston Z of the valvechamber,the valves are in equilibrium and will not move; but when the engineerdesires to apply the brakes he reduces the pressure in main orconducting pipe (1, which of course reduces the pressure on that side ofpiston Z. This disturbs the equilibrium of the valve, and as thepressure in the reservoir, and consequently that on the opposite face ofpiston Z, is greater than on the side next the main conducting-pipe a,the piston Z moves down, (or over, as the case may be,) causing valve orto connect port t with the exhaust 1), valve 0 to close port (Z, leadingto reservoir B, and to open port 9, leading from the valve-chamber O tothe opposite end of brake-cylinder A, whereupon the compressed air fromreservoir B passes by pipesf and h to cylinder A, and forces over itspiston, applying the brakes. The application of the brakes of coursereduces the pressure in reservoir 13. When the brakes are to be takenoff or released, the engineer increases the pressure in main pipe auntil it exceeds the pressure in the reservoir,

whereupon, the pressure on the pistonZof the valve, or in that side ofthe valve-chamber 0, being greater than on the opposite side, the pistonZ moves back into its former position, (shown in Figs. 2 and 3,)carrying with it the valves an 0, uncovering the ports (Z t, andconnecting port g with the exhaust q, permitting the compressed air topass by pipe 6 to the reservoir B, and by pipej to the cylinder A,taking off the brakes, as hereinbefore specified, while the air from theopposite end of the brake cylinder A escapes through pipes h, valve n,and exhaust-port q. To this part of the invention p rtains the means bywhich the control of the brakes is given to the conductor as well as tothe engineer, and this consists in a valve, a, placed on the main pipe aat any convenient point, to which is attached a conductors cord, so thathe may at will operate the valve so as to reduce the pressure in themain pipe a, and thus apply the brakes, a hereinbefore specified.

The next feature of the invention is the means whereby the brakes of anyone or more of the cars may be applied without applying the brakes ofthe remaining cars. For this purpose the end of the valve-rod m (seevalvechamber C, Fig. 8) is extended through the valve 12, and providedwith a cross-bar, t, to which is attached one end of a spiral spring, 8,the opposite end of said spring being attached to a stirrup or yoke, b,from which a rod, on, passes through a stuffing-box, 0, on thevalve-chamber C, and engages in a slot or oblong hole, p", in a radialarm, p. The radial arm (which is hinged, as at Q2, and held in positionby a spring, Q3, for purposes which will hereinafter appear) terminatesat one end in a spurred disk, 9, which is keyed to and operated by arod, F, suitably journaled, extending under the car, and provided withcranks H H. 13y turning the cranks H and rod F the spurred disk 9 isrotated, and with it the radial arm 19, to bring the desired tension orcompression on spring .9, and the spurred disk and radial arm p are thenlocked in position by a suitable dog or holding-pawl, B. In its normalcondition the spring sis inoperative, leaving the piston Z of the valvechamber 0 to be balanced by the equal pressure of the air on both of itsfaces and to move readily when the equilibrium is disturbed; but inproportion as the radial arm 1)" is raised in manner as hereinbeforespecified and pressure brought to bear on the spiral spring 8 will thevalve resist the pressure of the air in the reservoir 13, and thegreater will be the reduction of pressure in the main pipe to necessaryto cause the valve to move and open the pipe h leading to thebrake-cylinder A; but if the radial arm be lowered and the spring she intension, then a corresponding less reduction will be necessary tooperate the valve than when in its normal condition, thereby increasingthe range in pressure to operate the valve. Therefore, when the brakeson any given car or any group of cars are to be set without applying theremainder of the brakes, the springs s ofthe valves (of chamber 0) ofsuch cars are left without tension or compression, so that the piston Zwillmove on the slightest reduction of pressure in main pipe (1, whilethe springs s of the valves in chamber 0 on the remaining cars arecompressed more or less, so that a greater reduction of pressure in mainpipe (6 is required to operate them than is required for the firstmentioned. It Will be evident that by grading the compression of springss the brakes can be applied singly in succession or by groups insuccession at the will of the train officers. It is also evident that itthe spring 8, after being compressed,was allowed to act continuouslyupon the valve in valvechamber C, Fig. 3, there would come a time whenthe pressure in reservoir B (and the upper part oi" the valve-chainberC) so approached the pressure in the main pipe a that the power of thespring would draw up the valves, close theport g,andtake oftthe brakes'To prevent this, I provide devices duced pressure in main piped, whichdevices may be of the general character of those which I will nextdescribe. The radial arm pflwhich is pivoted to its spurred disk 9 andheld in position by a spring, (f, as before specified, is provided onits outer end wit-h a wheel, h, which engages between the travelingparallel bars 10'. (See Figs. 1 and 3.) These parallel travelingbars w"w are placed a distance apart about equal to the diameter of the wheelh, and have at their forward ends inclines which will engage the wheelon the end of the radial arm 1), whether the same be above or below theplane marking the space between the bars to w, and said bars are securedto and move with a bent rod,f, attached to the piston-rod z", andsupported at its free end by a bearin j, through which it moves and inwhich it is adjustable by means of a set-screw, 0. By means of theset-screw 1*, which may be placed in either of a series of holes in thebearing j, the rod f may be raised orlowered to change the plane whichthe traveling bars w w move and to adjust them with relation to theouter end of radial arm 1). If, now, the springs s of the valves invalve-chamber C have been compressed by elevating the arm p so as torequire agreater reduction of the pressure in the main pipe at to movethe 'valve, as soon as thevalve is moved and the compressed air from thereservoir B passes by pipe it into the cylinder A, on the commencementof the stroke of the piston to apply the brakes the movement of the bentrod f will carry with it the traveling bars 10 10, which engage the endof radial arm 9, and prevent it from rising to again compress the springor will force it down (as the case may be) to take the compression offof the spring and prevent its further action when the pressure in thereservoir B falls or approaches that in the main pipe a. The travelingbars are first intended to reduce the spring 8 to its normal condition,or by raising the plane of motion of the traveling bars, which willplace the spring 8 slightly in compression, and then operate valve toapply but a small pressure on piston of brakecylinder, as when theengineer wishes to slow up, the raising is done by set-screw 1-. Thereverse movement of the piston in brakc-cylinder A, when the brakes aretaken off as hereinbefore described, will of course cause the parallelbars 10 w to move in the opposite direction and release the radial arm1), which, rising, will restore the compression of the spring and theconsequent upward draft on the piston i.

In the foregoing description of these increased pressure and lockingdevices I have.

dial arm 12, may be used to counteract the force of springs when thepiston of brake-cylinder Ais first moved in applying the brakes. Thepressure used to apply the brakes is much greater than that required torelease them, and therefore to save in the quantity of air used torelease the brakes, as well as to prevent in a great degree the leakagearound the piston and packing of cylinder A while the brakes are beingreleased, I arrange in the line of pipej a reducing-valve, K, which Imay be of any of the several well-known and suitableconstructions. Inthe present instance it is shown as having somewhat the form of asafety-valve provided with a lever and a sliding weight, but no claim isherein made to the said construction, as it is especially reserved forthe subject-matter of another patcnt. A reducing-valve is also valuablein air-brakes, not only in the position shown in Figs. 1 and 2, and forthe purpose before specified, but is of great value when arranged on thepipe h, (or between the power and the piston in applying the'brake,) topermita change in the force applied to the brake when the car is loadedand when it is empty, and I wish the following matter to be understoodas applying to it when so placed as well as when located in the positionshown in Figs. 1 and 2.

Having thus set forth the nature and advantages of my invention, what Iclaim, and desire to secure by Letters Patent, is-

1. In an air-brake apparatus, the combination of a brake-cylinder, areservoir, a main air-supply, and a valve arranged with relation theretoso as to release the brakes by an increase in the main airsupply, andapply them by decreasing the same, as and for the purposes set forth.

2. In an air-brake apparatus, the combination of a brake-cylinder, areservoir, a main air-supply, an interposed valvechamber, a pistonarranged in the valve-chamber so that its opposite heads are subj ectedthe one to the prcssurein the main supply-pipe and the other to thepressure in the reservoir, valves actuated by said piston, air-pipeswhich lead to opposite ends of the brake-cylinder, and pipes leadingfrom the valve-chamber to the reservoir, one of said pipes beingprovided with a cheek-valve, substantially as and for the purposesspecified.

8. In an air-brake apparatus, the combination, with an air-reservoir, abrake-cylinder, and a main air-supply, of the valve-chamber having thetwo ports leading to the reservoir, the two ports leading to thebrakecylinder, and the exhaust-port, and the piston having the threeslide-valves which control said ports, substantially as and for thepurposes specified.

4. In an air-brake apparatus, the combina tion of a brake-cylinder, areservoir, a main supply-pipe, a valve-chamber provided with valvesactuated by disturbing the equilibrium of pressure in the reservoir andmain supplypipe, and a conductors valve located on the main supply-pipe,substantially as and for the purposes specified.

5. In an air-brake apparatus, the combination of a brake-cylinder, areservoir, a main supply-pipe, a valve-chamber provided with avalveactuated by disturbing the equilibrium of pressure in the mainsupply-pipe and reservoir, a spring-resistance for increasing theresistance of the valve to pressure in the reservoir, and a lockingdevice for restricting the action of the spring, substantially as andfor the purposes specified.

6. In an air-brake apparatus, the combination, with a balanced valve, ofan auxiliary spring, an adjustable radial spring-arn1, and travelinglocking-bars actuated from the piston-rod of the brake'cylinder,substantially as and for the purposes specified.

7. 1n air-brake apparatus, the combination,

presence of two witnesses, this 17th day of 5 May, 1884:.

, ROBERT M. MOKINNEY. \Vituesses:

JAMES M. NEVIN, JOHN N. XVHITE.

